Population Dynamics in Italian Canids between the Late Pleistocene and Bronze Age

Abstract

Dog domestication is still largely unresolved due to time-gaps in the sampling of regions. Ancient Italian canids are particularly understudied, currently represented by only a few specimens. In the present study, we sampled 27 canid remains from Northern Italy dated between the Late Pleistocene and Bronze Age to assess their genetic variability, and thus add context to dog domestication dynamics. They were targeted at four DNA fragments of the hypervariable region 1 of mitochondrial DNA. A total of 11 samples had good DNA preservation and were used for phylogenetic analyses. The dog samples were assigned to dog haplogroups A, C and D, and a Late Pleistocene wolf was set into wolf haplogroup 2. We present our data in the landscape of ancient and modern dog genetic variability, with a particular focus on the ancient Italian samples published thus far. Our results suggest there is high genetic variability within ancient Italian canids, where close relationships were evident between both a ~24,700 years old Italian canid, and Iberian and Bulgarian ancient dogs. These findings emphasize that disentangling dog domestication dynamics benefits from the analysis of specimens from Southern European regions.

Keywords: Italy; ancient DNA; archaeology; dogs; domestication; mitochondrial DNA; population genetics.

Figure 1

Map of the archaeological excavation locations from which the selected specimens were collected. Map created using QGIS [35].

Figure 2

Frequency of the four main mtDNA haplogroups (A–D) in Eurasia in different time periods. The X axis represents the age (BP), while the fill values represent the haplogroups abundance. The most recent dogs here considered are from Late Antiquity (Table S1).

Figure 3

Median Joining network based on the short fragment (57 bp) alignment containing ancient and modern dogs and ancient Italian wolves. European samples are shown in purple, Asian samples in blue. The red rings highlight haplotypes that contain both ancient Italian and Bulgarian samples (alongside modern samples); the yellow ring highlights a haplotype that contains, among others, ancient Italian, Iberian and Bulgarian samples. The four main canine haplogroups are highlighted in pink (Hg A), green (Hg B), purple (Hg C) and light blue (Hg D). Minor haplogroups E and F contain only modern individuals. Red dots represent median vectors. Samples included in the network are listed in the Table S1.

Figure 4

Bayesian tree of ancient and modern dogs and wolves based on the 360 bp database of mtDNA (Table S1). Samples from this study are highlighted in bold. Ancient canid specimens in the three enlargements are labeled with the respective country of origin and their approximate reported age. Monophyletic clusters of modern canid sequences are collapsed and identified by the dog clade to which they belong. PBrd denotes modern dog samples available from literature. The outgroup (a coyote) is not shown. Samples included in the tree are listed in the Table S1.